Fixes #14662. Return all EC parameters even for named curves

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15060)

1 files changed, 130 insertions, 74 deletions

diff --git a/crypto/ec/ec_backend.c b/crypto/ec/ec_backend.c
index 581c006fd0..6acfa21f69 100644
--- a/crypto/ec/ec_backend.c
+++ b/crypto/ec/ec_backend.c
@@ -150,61 +150,42 @@ char *ossl_ec_pt_format_id2name(int id)
     return NULL;
 }
 
-int ossl_ec_group_todata(const EC_GROUP *group, OSSL_PARAM_BLD *tmpl,
-                         OSSL_PARAM params[], OSSL_LIB_CTX *libctx,
-                         const char *propq,
-                         BN_CTX *bnctx, unsigned char **genbuf)
+static int ec_group_explicit_todata(const EC_GROUP *group, OSSL_PARAM_BLD *tmpl,
+                                    OSSL_PARAM params[], BN_CTX *bnctx,
+                                    unsigned char **genbuf)
 {
-    int ret = 0, curve_nid, encoding_flag;
-    const char *field_type, *encoding_name, *pt_form_name;
-    const BIGNUM *cofactor, *order;
-    BIGNUM *p = NULL, *a = NULL, *b = NULL;
-    point_conversion_form_t genform;
-    const EC_POINT *genpt;
-    unsigned char *seed = NULL;
-    size_t genbuf_len, seed_len;
-
-    if (group == NULL) {
-        ERR_raise(ERR_LIB_EC,EC_R_PASSED_NULL_PARAMETER);
-        return 0;
-    }
-
-    genform = EC_GROUP_get_point_conversion_form(group);
-    pt_form_name = ossl_ec_pt_format_id2name(genform);
-    if (pt_form_name == NULL
-        || !ossl_param_build_set_utf8_string(
-                tmpl, params,
-                OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT, pt_form_name)) {
-        ECerr(0, EC_R_INVALID_FORM);
-        return 0;
-    }
-    encoding_flag = EC_GROUP_get_asn1_flag(group) & OPENSSL_EC_NAMED_CURVE;
-    encoding_name = ec_param_encoding_id2name(encoding_flag);
-    if (encoding_name == NULL
-        || !ossl_param_build_set_utf8_string(tmpl, params,
-                                             OSSL_PKEY_PARAM_EC_ENCODING,
-                                             encoding_name)) {
-        ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
+    int ret = 0, fid;
+    const char *field_type;
+    const OSSL_PARAM *param = NULL;
+    const OSSL_PARAM *param_p = NULL;
+    const OSSL_PARAM *param_a = NULL;
+    const OSSL_PARAM *param_b = NULL;
+
+    fid = EC_GROUP_get_field_type(group);
+
+    if (fid == NID_X9_62_prime_field) {
+        field_type = SN_X9_62_prime_field;
+    } else if (fid == NID_X9_62_characteristic_two_field) {
+#ifdef OPENSSL_NO_EC2M
+        ERR_raise(ERR_LIB_EC, EC_R_GF2M_NOT_SUPPORTED);
+        goto err;
+#else
+        field_type = SN_X9_62_characteristic_two_field;
+#endif
+    } else {
+        ERR_raise(ERR_LIB_EC, EC_R_INVALID_FIELD);
         return 0;
     }
 
-    curve_nid = EC_GROUP_get_curve_name(group);
-    if (curve_nid == NID_undef) {
-        /* explicit curve */
-        int fid = EC_GROUP_get_field_type(group);
-
-        if (fid == NID_X9_62_prime_field) {
-            field_type = SN_X9_62_prime_field;
-        } else if (fid == NID_X9_62_characteristic_two_field) {
-            field_type = SN_X9_62_characteristic_two_field;
-        } else {
-            ERR_raise(ERR_LIB_EC, EC_R_INVALID_FIELD);
-            return 0;
-        }
+    param_p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_P);
+    param_a = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_A);
+    param_b = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_B);
+    if (tmpl != NULL || param_p != NULL || param_a != NULL || param_b != NULL)
+    {
+        BIGNUM *p = BN_CTX_get(bnctx);
+        BIGNUM *a = BN_CTX_get(bnctx);
+        BIGNUM *b = BN_CTX_get(bnctx);
 
-        p = BN_CTX_get(bnctx);
-        a = BN_CTX_get(bnctx);
-        b = BN_CTX_get(bnctx);
         if (b == NULL) {
             ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
             goto err;
@@ -214,13 +195,45 @@ int ossl_ec_group_todata(const EC_GROUP *group, OSSL_PARAM_BLD *tmpl,
             ERR_raise(ERR_LIB_EC, EC_R_INVALID_CURVE);
             goto err;
         }
+        if (!ossl_param_build_set_bn(tmpl, params, OSSL_PKEY_PARAM_EC_P, p)
+            || !ossl_param_build_set_bn(tmpl, params, OSSL_PKEY_PARAM_EC_A, a)
+            || !ossl_param_build_set_bn(tmpl, params, OSSL_PKEY_PARAM_EC_B, b)) {
+            ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+    }
+
+    param = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_ORDER);
+    if (tmpl != NULL || param != NULL) {
+        const BIGNUM *order = EC_GROUP_get0_order(group);
 
-        order = EC_GROUP_get0_order(group);
         if (order == NULL) {
             ERR_raise(ERR_LIB_EC, EC_R_INVALID_GROUP_ORDER);
             goto err;
         }
-        genpt = EC_GROUP_get0_generator(group);
+        if (!ossl_param_build_set_bn(tmpl, params, OSSL_PKEY_PARAM_EC_ORDER,
+                                    order)) {
+            ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+    }
+
+    param = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_FIELD_TYPE);
+    if (tmpl != NULL || param != NULL) {
+        if (!ossl_param_build_set_utf8_string(tmpl, params,
+                                              OSSL_PKEY_PARAM_EC_FIELD_TYPE,
+                                              field_type)) {
+            ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+    }
+
+    param = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_GENERATOR);
+    if (tmpl != NULL || param != NULL) {
+        size_t genbuf_len;
+        const EC_POINT *genpt = EC_GROUP_get0_generator(group);
+        point_conversion_form_t genform = EC_GROUP_get_point_conversion_form(group);
+
         if (genpt == NULL) {
             ERR_raise(ERR_LIB_EC, EC_R_INVALID_GENERATOR);
             goto err;
@@ -230,32 +243,31 @@ int ossl_ec_group_todata(const EC_GROUP *group, OSSL_PARAM_BLD *tmpl,
             ERR_raise(ERR_LIB_EC, EC_R_INVALID_GENERATOR);
             goto err;
         }
-
-        if (!ossl_param_build_set_utf8_string(tmpl, params,
-                                              OSSL_PKEY_PARAM_EC_FIELD_TYPE,
-                                              field_type)
-            || !ossl_param_build_set_bn(tmpl, params, OSSL_PKEY_PARAM_EC_P, p)
-            || !ossl_param_build_set_bn(tmpl, params, OSSL_PKEY_PARAM_EC_A, a)
-            || !ossl_param_build_set_bn(tmpl, params, OSSL_PKEY_PARAM_EC_B, b)
-            || !ossl_param_build_set_bn(tmpl, params, OSSL_PKEY_PARAM_EC_ORDER,
-                                        order)
-            || !ossl_param_build_set_octet_string(tmpl, params,
-                                                  OSSL_PKEY_PARAM_EC_GENERATOR,
-                                                  *genbuf, genbuf_len)) {
+        if (!ossl_param_build_set_octet_string(tmpl, params,
+                                               OSSL_PKEY_PARAM_EC_GENERATOR,
+                                               *genbuf, genbuf_len)) {
             ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
             goto err;
         }
+    }
+
+    param = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_COFACTOR);
+    if (tmpl != NULL || param != NULL) {
+        const BIGNUM *cofactor = EC_GROUP_get0_cofactor(group);
 
-        cofactor = EC_GROUP_get0_cofactor(group);
         if (cofactor != NULL
             && !ossl_param_build_set_bn(tmpl, params,
                                         OSSL_PKEY_PARAM_EC_COFACTOR, cofactor)) {
             ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
             goto err;
         }
+    }
+
+    param = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_SEED);
+    if (tmpl != NULL || param != NULL) {
+        unsigned char *seed = EC_GROUP_get0_seed(group);
+        size_t seed_len = EC_GROUP_get_seed_len(group);
 
-        seed = EC_GROUP_get0_seed(group);
-        seed_len = EC_GROUP_get_seed_len(group);
         if (seed != NULL
             && seed_len > 0
             && !ossl_param_build_set_octet_string(tmpl, params,
@@ -264,14 +276,58 @@ int ossl_ec_group_todata(const EC_GROUP *group, OSSL_PARAM_BLD *tmpl,
             ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
             goto err;
         }
-#ifdef OPENSSL_NO_EC2M
-        if (fid == NID_X9_62_characteristic_two_field) {
-            ERR_raise(ERR_LIB_EC, EC_R_GF2M_NOT_SUPPORTED);
+    }
+    ret = 1;
+err:
+    return ret;
+}
+
+int ossl_ec_group_todata(const EC_GROUP *group, OSSL_PARAM_BLD *tmpl,
+                         OSSL_PARAM params[], OSSL_LIB_CTX *libctx,
+                         const char *propq,
+                         BN_CTX *bnctx, unsigned char **genbuf)
+{
+    int ret = 0, curve_nid, encoding_flag;
+    const char *encoding_name, *pt_form_name;
+    point_conversion_form_t genform;
+
+    if (group == NULL) {
+        ERR_raise(ERR_LIB_EC,EC_R_PASSED_NULL_PARAMETER);
+        return 0;
+    }
+
+    genform = EC_GROUP_get_point_conversion_form(group);
+    pt_form_name = ossl_ec_pt_format_id2name(genform);
+    if (pt_form_name == NULL
+        || !ossl_param_build_set_utf8_string(
+                tmpl, params,
+                OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT, pt_form_name)) {
+        ERR_raise(ERR_LIB_EC, EC_R_INVALID_FORM);
+        return 0;
+    }
+    encoding_flag = EC_GROUP_get_asn1_flag(group) & OPENSSL_EC_NAMED_CURVE;
+    encoding_name = ec_param_encoding_id2name(encoding_flag);
+    if (encoding_name == NULL
+        || !ossl_param_build_set_utf8_string(tmpl, params,
+                                             OSSL_PKEY_PARAM_EC_ENCODING,
+                                             encoding_name)) {
+        ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
+        return 0;
+    }
+
+    curve_nid = EC_GROUP_get_curve_name(group);
+
+    /*
+     * Get the explicit parameters in these two cases:
+     * - We do not have a template, i.e. specific parameters are requested
+     * - The curve is not a named curve
+     */
+    if (tmpl == NULL || curve_nid == NID_undef)
+        if (!ec_group_explicit_todata(group, tmpl, params, bnctx, genbuf))
             goto err;
-        }
-#endif
-    } else {
-        /* named curve */
+
+    if (curve_nid != NID_undef) {
+        /* Named curve */
         const char *curve_name = ossl_ec_curve_nid2name(curve_nid);
 
         if (curve_name == NULL